BONES OF THE FACE 



121 



Accessory palatine foramina are also present. The palatine groove is usually not 

 very distinct. The palatine canal is formed entirely in this part, and there is no 

 articulation with the vomer. A rounded ridge occurs on the nasal side of the 

 median suture. The interior is hollow, forming part of the palatine sinus. The 

 perpendicular part is an extensive, quadrilateral, thin plate, which forms the pos- 

 terior part of the lateral wall of the nasal cavity and in part bounds the narrow pos- 

 terior nares. Its internal surface is nearly flat, and is smooth and free, except 

 behind, where it is overlapped by the pterygoid bone. The external surface is 

 attached to a small extent to the pterygoid process l^ehind, and is free elsewhere. 

 The spheno-palatine foramen is a long elliptical opening, formed by a deep notch in 

 the upper edge of the palate bone and completed by the ethmoid and sphenoid. 

 The edge behind this foramen articulates with the orbital wing of the sphenoid, 

 not the frontal as in the horse. 



The pterygoid bone is wider than in the horse, and forms the greater part of the 

 lateral boundary of the posterior nares. Its outer surface is almost entirely united 



Fir,. 93. — Median Section of Skull op Ox, Without the Mandible. 

 The mucous membrane is retained. The septum nasi is removed, a, Superior meatus; b, middle meatus, 

 with b' and b", its upper and lower divisions; c, inferior meatus; d, superior turbinal; e, superior turbinal fold; 

 /, inferior turbinal; g, alar fold; h, inferior turbinal fold; i, lateral mass of ethmoid (ethmoturbinals); ;', large 

 ethmoturbinal or middle turbinal; k, frontal sinus; /, sphenoidal sinus; m, cranial cavity; n, palatine sinus; 

 o, nasal bone; o', parietal cartilage; p, palate process of maxilla; q, palate bone (horizontal part); 1, sphenoid 

 bone; 2, 3, inner and outer plates of frontal bone; 4, 4', outer and inner plates of parietal bone; 5, 5' , occipital 

 bone; 5", condyloid and hypoglossal foramina; 6, paramastoid or styloid process; 6' , occipital condyle; 7, 

 petrous temporal bone; 7', internal auditory meatus; S, squamous temporal bone; 9, muscular process; 10, 

 pterygoid bone (hamulus), (.\fter EUenberger, in Leisering's Atlas.) 



to the palate bone and the pterygoid process, Init a small part is free in the pterygo- 

 palatine fossa. The hamulus is distinctly hook-like, thin, and sharp. 



The nasal bone is little more than half the length of that of the horse. It is 

 straight in its length, but strongly curved from side to side. It does not fuse later- 

 ally with the adjacent bones, even in old age. The posterior extremity is pointed 

 and fits into the notch between the frontal bones. The anterior end is broader, 

 and is divided into two parts by a deep notch. In old animals there is a small 

 extension of the frontal sinus into this bone. 



The lacrimal bone is very large. The extensive facial part is concave in its 

 length, and bears no lacrimal tubercle. The orbital margin is marked ])y several 

 notches. The orl)ital part forms below the remarkable lacrimal bulla; this is a 

 large and very thin-walled protuberance, which bulges backward into the lower 

 part of the orbit, and contains an extension of the maxillary sinus. The lacrimal 

 fossa is small, and is just behind the orbital margin. 



The malar bone is relatively long. The facial surface is extensive; it bears a 

 curved crest (Crista facialis) just below the orbital margin, and below this it is 

 concave from above downward. The zygomatic process divides into two branches; 



